<template>
  <el-tree
    :data="data"
    show-checkbox
    default-expand-all
    node-key="id"
    ref="tree"
    highlight-current
    :props="defaultProps"
  ></el-tree>

  <div class="buttons">
    <el-button @click="getCheckedNodes">通过 node 获取</el-button>
    <el-button @click="getCheckedKeys">通过 key 获取</el-button>
    <el-button @click="setCheckedNodes">通过 node 设置</el-button>
    <el-button @click="setCheckedKeys">通过 key 设置</el-button>
    <el-button @click="resetChecked">清空</el-button>
  </div>
</template>

<script>
export default {
  methods: {
    getCheckedNodes() {
      console.log(this.$refs.tree.getCheckedNodes())
    },
    getCheckedKeys() {
      console.log(this.$refs.tree.getCheckedKeys())
    },
    setCheckedNodes() {
      this.$refs.tree.setCheckedNodes([
        {
          id: 5,
          label: '二级 2-1'
        },
        {
          id: 9,
          label: '三级 1-1-1'
        }
      ])
    },
    setCheckedKeys() {
      this.$refs.tree.setCheckedKeys([3])
    },
    resetChecked() {
      this.$refs.tree.setCheckedKeys([])
    }
  },

  data() {
    return {
      data: [
        {
          id: 1,
          label: '一级 1',
          children: [
            {
              id: 4,
              label: '二级 1-1',
              children: [
                {
                  id: 9,
                  label: '三级 1-1-1'
                },
                {
                  id: 10,
                  label: '三级 1-1-2'
                }
              ]
            }
          ]
        },
        {
          id: 2,
          label: '一级 2',
          children: [
            {
              id: 5,
              label: '二级 2-1'
            },
            {
              id: 6,
              label: '二级 2-2'
            }
          ]
        },
        {
          id: 3,
          label: '一级 3',
          children: [
            {
              id: 7,
              label: '二级 3-1'
            },
            {
              id: 8,
              label: '二级 3-2'
            }
          ]
        }
      ],
      defaultProps: {
        children: 'children',
        label: 'label'
      }
    }
  }
}
</script>

<style></style>
